In January 1969, one of the most promising young lieutenant colonels the US Army had ever seen touched down in Vietnam for his second tour of duty, which would turn out to be his most daring and legendary. David H. Hackworth had just completed the writing of a tactical handbook for the Pentagon, and now he had been ordered to put his counterguerilla-fighting theories into action. He was given the morale-drained 4/39th--a battalion of...